# ---
# title: 299. Bulls and Cows
# id: problem299
# author: Tian Jun
# date: 2020-10-31
# difficulty: Medium
# categories: Hash Table
# link: <https://leetcode.com/problems/bulls-and-cows/description/>
# hidden: true
# ---
# 
# You are playing the **[Bulls and
# Cows](https://en.wikipedia.org/wiki/Bulls_and_Cows)** game with your friend.
# 
# You write down a secret number and ask your friend to guess what the number
# is. When your friend makes a guess, you provide a hint with the following
# info:
# 
#   * The number of "bulls", which are digits in the guess that are in the correct position.
#   * The number of "cows", which are digits in the guess that are in your secret number but are located in the wrong position. Specifically, the non-bull digits in the guess that could be rearranged such that they become bulls.
# 
# Given the secret number `secret` and your friend's guess `guess`, return _the
# hint for your friend 's guess_.
# 
# The hint should be formatted as `"xAyB"`, where `x` is the number of bulls and
# `y` is the number of cows. Note that both `secret` and `guess` may contain
# duplicate digits.
# 
# 
# 
# **Example 1:**
# 
#     
#     
#     Input: secret = "1807", guess = "7810"
#     Output: "1A3B"
#     Explanation: Bulls are connected with a '|' and cows are underlined:
#     "1807"
#       |
#     " _7_ 8 _10_ "
# 
# **Example 2:**
# 
#     
#     
#     Input: secret = "1123", guess = "0111"
#     Output: "1A1B"
#     Explanation: Bulls are connected with a '|' and cows are underlined:
#     "1123"        "1123"
#       |      or     |
#     "01 _1_ 1"        "011 _1_ "
#     Note that only one of the two unmatched 1s is counted as a cow since the non-bull digits can only be rearranged to allow one 1 to be a bull.
#     
# 
# **Example 3:**
# 
#     
#     
#     Input: secret = "1", guess = "0"
#     Output: "0A0B"
#     
# 
# **Example 4:**
# 
#     
#     
#     Input: secret = "1", guess = "1"
#     Output: "1A0B"
#     
# 
# 
# 
# **Constraints:**
# 
#   * `1 <= secret.length, guess.length <= 1000`
#   * `secret.length == guess.length`
#   * `secret` and `guess` consist of digits only.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
